/*
 * Copyright (C) 2011 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.gallery3d.data;

import com.android.gallery3d.util.Future;

import java.util.ArrayList;

// ComboAlbum combines multiple media sets into one. It lists all media items
// from the input albums.
// This only handles SubMediaSets, not MediaItems. (That's all we need now)
public class ComboAlbum extends MediaSet implements ContentListener {
	private static final String TAG = ComboAlbum.class.getSimpleName();
	private final MediaSet[] mSets;
	private String mName;

	public ComboAlbum(Path path, MediaSet[] mediaSets, String name) {
		super(path, nextVersionNumber());
		Log.d(TAG, "ComboAlbum");
		mSets = mediaSets;
		for (MediaSet set : mSets) {
			set.addContentListener(this);
		}
		mName = name;
	}

	@Override
	public ArrayList<MediaItem> getMediaItem(int start, int count) {
		Log.d(TAG, "getMediaItem -- start: " + start + " count: " + count);
		ArrayList<MediaItem> items = new ArrayList<MediaItem>();
		for (MediaSet set : mSets) {
			int size = set.getMediaItemCount();
			if (count < 1)
				break;
			if (start < size) {
				int fetchCount = (start + count <= size) ? count : size - start;
				ArrayList<MediaItem> fetchItems = set.getMediaItem(start,
						fetchCount);
				items.addAll(fetchItems);
				count -= fetchItems.size();
				start = 0;
			} else {
				start -= size;
			}
		}
		return items;
	}

	@Override
	public int getMediaItemCount() {
		Log.d(TAG, "getMediaItemCount");
		int count = 0;
		for (MediaSet set : mSets) {
			count += set.getMediaItemCount();
		}
		return count;
	}

	@Override
	public boolean isLeafAlbum() {
		return true;
	}

	@Override
	public String getName() {
		return mName;
	}

	public void useNameOfChild(int i) {
		if (i < mSets.length)
			mName = mSets[i].getName();
	}

	@Override
	public long reload() {
		Log.d(TAG, "reload");
		boolean changed = false;
		for (int i = 0, n = mSets.length; i < n; ++i) {
			long version = mSets[i].reload();
			if (version > mDataVersion)
				changed = true;
		}
		if (changed)
			mDataVersion = nextVersionNumber();
		return mDataVersion;
	}

	@Override
	public void onContentDirty() {
		notifyContentChanged();
	}

	@Override
	public Future<Integer> requestSync(SyncListener listener) {
		Log.d(TAG, "requestSync");
		return requestSyncOnMultipleSets(mSets, listener);
	}
}
